Strategic Defense Initiative examines developments in the technologies currently being researched under SDI. The OTA does not repeat the work of its earlier reports but gives special attention to filling in gaps in those reports and to describing technical progress made in the intervening period. The report also presents information on the prospects for functional survival against preemptive attack of alternative ballistic missile defense system architectures now being considered under the SDI. Finally, it analyzes the feasibility of developing reliable software to perform the battle management tasks required by such system architectures. Originally published in 1988. The Princeton Legacy Library uses the latest print-on-demand technology to again make available previously out-of-print books from the distinguished backlist of Princeton University Press. These paperback editions preserve the original texts of these important books while presenting them in durable paperback editions. The goal of the Princeton Legacy Library is to vastly increase access to the rich scholarly heritage found in the thousands of books published by Princeton University Press since its founding in 1905.